Implant for treatment of a heart valve, in particular a mitral valve, material including such an implant, and material for insertion thereof

ABSTRACT

This implant ( 1 ) is formed by a helically wound wire ( 2 ). According to the invention, it has dimensions such that it is able to be screwed into the wall of the annulus ( 103 ) and/or into the cardiac wall ( 101 ) adjoining this annulus ( 103 ) such that a portion of said annulus ( 103 ) and/or of said wall ( 101 ) is located in the perimeter of the implant ( 1 ); and it comprises at least one first coil able, during said screwing of the implant ( 1 ), to insert itself into said wall while having a first dimension and at least one second coil having a second dimension, or adopting this second dimension after implantation, said second dimension being smaller than the first dimension such that the implant ( 1 ), once inserted, enables contraction of said wall portion located in the perimeter of this implant ( 1 ).

The present invention concerns an implant for treatment of a heartvalve, in particular a mitral valve of a heart, a material includingsuch an implant and a material for insertion thereof. The treatment inquestion may consist of performing an annuloplasty, i.e. reducing adistension of the annulus, or strengthening the annulus of a normalvalve. The invention also concerns a percutaneous intervention methodfor performing such a treatment.

The annulus of a heart valve can, over time, undergo a distensionleading to poor coaptation of the leaflets, resulting in a loss ofsealing of the valve.

To treat this affection, it is well known to perform an annuloplasty,i.e. re-calibration of the annulus using an implant inserted on thevalvular annulus.

This annuloplasty implant can be a prosthetic annulus fixed on thenative valvular annulus. This technique does, however, have the drawbackof involving an open-heart operation.

The annuloplasty implant can also be a deformable elongated member, ableto be introduced using a catheter through a minimally-invasive vascularapproach, then able to be delivered via the catheter and fixed near thevalvular annulus before being circumferentially retracted.

The existing annuloplasty implants of this type, and the correspondingimplantation techniques, like the systems using the coronary sinuses,are not, however, fully satisfactory.

One existing implant, described by document N° WO 2006/091163, is formedby a helically wound wire, forming a split annulus having dimensionsclose to those of the valvular annulus. This implant is designed to beengaged on the base of the leaflets and to grip this base.

Moreover, it may be necessary to implant a prosthetic heart valve, inparticular percutaneously using a catheter. Currently, this type ofimplantation is difficult on the mitral valve of a heart,percutaneously, essentially due to the fact that the annulus of a mitralvalve is elastic and risks becoming distended upon percutaneousimplantation of a prosthetic valve.

The present invention essentially aims to resolve the drawbacks and gapsof the prior art.

This implant is, in a known manner, made up of a helically-wound wire.

To this end, the implant according to the invention

-   -   has dimensions such that it is able to be screwed into the wall        of the annulus and/or into the cardiac wall adjoining this        annulus such that one portion of this annulus and/or of this        wall is located in the perimeter of the implant; and    -   comprises at least one coil able, during said screwing of the        implant, to be inserted in said wall while having a first        dimension and at least one second coil having a second        dimension, or adopting this second dimension after implantation,        said second dimension being smaller than the first dimension        such that the implant, once inserted, enables a contraction of        said wall portion located in the perimeter of this implant.

The implant according to the invention thus has much smaller dimensionsthan those of the annulus of the valve to be treated, such that it canbe placed locally in the wall of this annulus and/or in the cardiac walladjoining this annulus. By “much smaller dimensions”, one mustunderstand that the implant has, in the plane perpendicular to itsscrewing axis, a maximum dimension at most equal to 15 mm, and generallyin the vicinity of 10 mm, or smaller than 10 mm. This implant can havecircular coils; said first coil(s) then have an external diameter of atmost 15 mm. The implant can also have elliptical coils; said first coilsthen have a dimension of at most 15 mm along their largest axis.

“Screwing of the implant” designates a rotation of the implant along itsaxis, done so as to cause the helical coil formed by this implant tomove in a direction. Below, the terms “front” and “rear” will designatethe parts of the implant located on the front side or the rear side,respectively, in relation to the direction of screwing.

The implant is simply placed in the annulus and/or the cardiac wall,along a direction more or less perpendicular to the plane of theannulus, and makes it possible to achieve a local contraction of thetissue constituting this annulus and/or this wall. This contractionperforms, in whole or in part, the annuloplasty. The radial contractionthus done also allows local strengthening of the annulus.

When said radial contraction only partially performs the aforementionedannuloplasty and/or strengthening, a plurality of implants according tothe invention can be inserted closer and closer on the annulus and/orthe wall, or on a portion of this annulus and/or this wall, to performall of the desired annuloplasty and/or strengthening.

According to one possible formation of the coils, said first coil(s) arelocated, in the direction of screwing of the implant, in front of saidsecond coil(s).

During screwing of the implant, said first coil(s) penetrate first intothe annulus and/or the cardiac wall and form a path having correspondingdimensions, which will then be used by said second coil(s), of smallerdimensions, thereby bringing about the radial contraction of saidportion of the annulus and/or wall.

The coils of the implant can be circular, as already mentioned, or havea non-circular shape, in particular oval or elliptical.

The implant performs an additional contraction of the annulus and/or ofsaid adjoining wall according to its angular position in this annulusand/or this wall.

According to another possible formation of the coils, the wire making upthe implant is in a shape memory material, defining, in a first state,coils having said first dimension and, in a second state, coils havingsaid second dimension.

The passage of these coils from said first dimension to said seconddimension, by shape memory, causes the contraction of said portion ofthe annulus located in the perimeter of these coils of the implant.

The possible formations of the coils mentioned above can be combined ona same implant. Thus, for example, an implant can comprise at least onecoil having a larger diameter and at least one coil having a smallerdiameter, and be in a shape memory material such that the diameter ofthe coils is reduced after implantation; an implant can be in a shapememory material such that it comprises circular coils at the time of itsimplantation, assuming a non-circular shape after implantation.

The front end of the wire constituted by the implant is preferablypointed or sharp, so as to facilitate its penetration into the tissue ofthe annulus and/or said cardiac wall.

The wire constituting the implant can have a same structure along itsentire length, or comprise portions in a first material and portions ina second material different from the first material. For example, theimplant can comprise portions in non-shape memory wire and portions inshape memory wire; the implant can comprise portions of wire in anon-resorptive material and portions of wire in a resorptive material.

The wire constituting the implant can for example be in stainless steelor in a shape memory material such as an alloy of nickel and titaniumknown by the name “nitinol”, or in a material using superelasticity, orin a resorptive material.

The wire constituting the implant can also comprise portions ofdifferent structures, for example solid, resistant portions and portionshaving a thinner cross-section able to be broken in the event of radialforces directed toward the exterior. In this second case, the implantcan, for example, be used on children, and break under the effort ofsaid stresses resulting from the growth of the patient.

The implant can comprise radiopaque markers enabling its visualizationthrough the patient's body, in particular markers enabling visualizationof the angular orientation of the implant when the latter comprisesnon-circular coils.

The implant can also comprise means ensuring its anchoring in the tissuewith regard to screwing or unscrewing; for example, a rear portion ofthe wire can, by shape memory, bore itself in such that the wire can nolonger slide in relation to the tissue in which the implant is placed;the implant can also comprise protruding portions, for example in theform of claws, deploying via shape memory.

The material including the implant according to the invention comprisesmeans making it possible to connect at least two adjacent implantsplaced in an annulus, so as to achieve a contraction of the wall of theannulus located between the implants, in addition to the contractionachieved by the implants themselves. It can in particular involve wiresin a material able to be twisted, in particular in a metallic material,connected to the proximal parts of the implants, these wires beingengaged in a same catheter then being twisted in order to bring the twoimplants closer together.

It can also involve wires or strips in metal or in a material usingsuperelasticity, or a shape memory material connecting two implants,able to be shortened after implantation.

The material for insertion of an implant according to the inventionincludes at least one catheter able to deliver the implant, means forlongitudinal movement of the implant in relation to this catheter andmeans for driving the implant in rotation along the axis of the implant.

The material according to the invention thus enables precise insertionof the implant, using a minimally-invasive approach.

The longitudinal movement means may comprise a push-rod slidinglyengaged in the catheter.

The rotational driving means may comprise a wire separably connected tothe rear end of the implant.

The separability of the wire connected to the rear end of the implantcan in particular be achieved via a removable connection of this wireand this end, in particular using an assembly via reversible locking,being released via traction on the wire.

The percutaneous intervention method according to the inventioncomprises the steps consisting of:

-   -   using the implant and the material as mentioned above;    -   bringing the distal opening of the catheter comprised by the        material across from the area designed to receive the implant;    -   causing the implant to move forward in relation to the catheter        while driving this implant in rotation along its axis, in order        to perform screwing of the implant into the annulus of the valve        to be treated and/or the cardiac wall adjoining this annulus;    -   if needed, repeat the preceding steps so as to insert as many        implants as necessary to perform the desired annuloplasty and/or        the strengthening of the annulus.

The step consisting of bringing the distal opening of the catheteracross from the area designed to receive the implant may be done byapproaching the valve via one or the other of the sides of this valve,in particular, involving the treatment of a mitral valve, either via aventricular approach or an auricular approach.

The invention will be well understood, and other characteristics andadvantages thereof will appear, in reference to the appendeddiagrammatic drawing, illustrating, as non-limiting examples, severalpossible embodiments of the implant and the material it concerns.

FIG. 1 is a perspective view of the implant according to a firstembodiment;

FIG. 2 is a perspective view of the implant according to a secondembodiment;

FIG. 3 is a flat diagrammatic view of a coil of the implant;

FIG. 4 is a flat diagrammatic view of a coil of another implant;

FIG. 5 is a view of a heart in partial cross-section, during a firststep of insertion of the implant according to the invention;

FIGS. 6 to 9 are views of four successive steps for insertion of theimplant;

FIG. 10 is a view of the implant along a direction perpendicular to FIG.9;

FIG. 11 is an outline sketch of a mitral valve in which three implantshave been inserted;

FIG. 12 is a side view of a push-rod comprised by the material accordingto the invention;

FIG. 13 is an end view of this push-rod;

FIG. 14 is a view of one variation of embodiment of the materialaccording to the invention;

FIG. 15 is a view of another variation of embodiment of the materialaccording to the invention;

FIGS. 16 and 17 are still further views of another variation ofembodiment of the material according to the invention;

FIG. 18 is a view of another embodiment of the implant according to theinvention;

FIGS. 19 to 22 are views of yet another embodiment of the implantaccording to the invention, during four successive steps of insertion;

FIGS. 23 to 30 are views of yet another embodiment of the materialaccording to the invention;

FIG. 31 is a partial perspective view of a heart annulus having a seriesof implants according to another embodiment, placed in its wall, and

FIG. 32 is an enlarged perspective view of two implants from this seriesof implants.

FIG. 1 illustrates an implant 1 for treatment of a heart valve, inparticular a mitral valve of a heart, this treatment being able toconsist of performing an annuloplasty, i.e. reducing a distension of theannulus, or strengthening the annulus of a normal valve.

As illustrated, the implant 1 is formed by a helically wound wire 2 andcomprises a conical portion 3 and a cylindrical portion 4. The conicalportion 3 is made up of coils whereof the diameter decreases in thedirection of the cylindrical portion 4, which is formed by coils havinga constant diameter.

The end 5 of the wire 2 at the level of the coil having the largestdiameter of the conical portion 3 is pointed, so as to be able to piercethe tissue constituting the annulus of a mitral valve and/or the wall ofthe ventricle adjoining this annulus.

FIG. 2 illustrates an implant 1 having a similar structure but having apurely conical shape, i.e. comprising coils whereof the diameterdecreases from one end of the implant to the other.

FIG. 3 shows that the implant 1 can have circular coils and FIG. 4 showsthat the implant 1 can comprise coils having an elliptical shape.

FIGS. 5 to 10 show one possible procedure for inserting one or the otherof the aforementioned implants 1.

During a first step, a catheter containing a hollow piercing needle isintroduced via the aorta 100, up to the left ventricle 101 then isengaged between the pillars 102 until the distal end of the catheterarrives against the ventricular wall in the immediate vicinity of theannulus 103 of the mitral valve. To follow this journey, the cathetercan present appropriate successive curves or can be of the “deflectable”type, i.e. able to be oriented using sliding wires which it comprises inits wall.

Once this catheter is in place, the needle is deployed to pierce theventricular wall, and a guide wire 10 is slid through this needle to theinside of the left auricular appendix 104.

The catheter is then removed while still keeping the wire 10 in place,and another catheter 11, containing the implant 1, is slid on the wire10 until its distal opening is in the immediate vicinity of the mitralannulus 103, as shown by FIG. 5.

It appears in FIG. 6 that this catheter 11 comprises two diametricallyopposed ducts 12 wherein are engaged and can slide two wires 13 whereofthe distal ends are bent. These distal ends are elastically deformablesuch that they can adopt a substantially rectilinear shape enabling thewires 13 to slide in the ducts 12, and resume their neutral curved shapewhen they are outside these ducts 12.

Once the distal end of the catheter 11 is in contact with theventricular wall, these distal ends are deployed outside the ducts 12and penetrate inside this ventricular wall, ensuring that the catheter11 is kept in position.

The implant 1 is contained in its stressed state in the catheter 11, andits rear end is removably connected, by reversible locking, to a wire14. This wire 14 is engaged through a radially offset opening 15comprised by the distal end wall of a hollow push-rod 16 engaged in thecatheter 11, this push-rod 16 being able to pivot in the lumen of thecatheter 11.

FIGS. 12 and 13 more particularly show the push-rod 16 and its opening15.

The push-rod 16 is used to screw the implant 1 into the ventricularwall, i.e. to move this implant 1 longitudinally in relation to thecatheter 11 so as to remove the latter while driving it in rotationaround its axis. During this screwing, the first coil having the largestdiameter first penetrates the ventricular wall and forms a pathcorresponding to its diameter, which will then be used by the followingcoil of smaller diameter, and so on (cf. FIGS. 7 and 8). Each coil ofsmaller diameter then produces a radial contraction of the portion ofthe ventricular wall located in the perimeter of the path pierced by thefirst coil. This contraction thus makes it possible to reduce thediameter of the annulus 103, performing, in whole or in part, anannuloplasty and/or a local strengthening of the annulus.

When the implant 1 is completely screwed into the ventricular wall, thepush-rod 16 is removed and the wire 14 is separated from the implant 1,by traction so as to release the reversible locking whereby this wire 14is connected to the implant 1. The wires 13 are then retracted, and thecatheter 11 and then the guide wire 10 are removed (cf. FIGS. 9 and 10).

When required by the annuloplasty to be performed, several implants areinserted side by side, in particular three implants in the example shownin FIG. 10.

The wire 2 can be made of a shape memory material such that the coils itforms can naturally go outside the catheter 11 during forward progressof an implant 1 outside this catheter 11.

FIG. 14 shows that the wire 10 can comprise branches 10 a deployable byelasticity or shape memory, which make it possible to produce a certainretention of this wire 10 in the auricular appendix 104. These branches10 a can, however, pivot from the side of the free end of the wire 10when tension is exerted on the latter, such that the removal of thiswire remains possible.

FIG. 15 shows that, according to another embodiment of the invention,the wire 10 comprises deployable branches 10 b, enabling anchoring of adistal portion 10 c of the wire 10 in the ventricular wall, this distalportion 10 c being separably connected, in particular by reversiblelocking, to the rest of the wire 10. This distal portion 10 c remains inplace after insertion of the implant 1.

FIGS. 16 and 17 show that the implant 1 can be inserted via theauricular side of the mitral valve. The wire is “captured” according tothe so-called “lasso” technique by the loop 20 a of another wire 20,introduced using a transseptal approach. The wire 10 is then pulled toallow guiding of the catheter 11 by the same transseptal approach, andplacement of the implant 1 using a technique similar to that previouslydescribed.

FIG. 18 shows, very diagrammatically, a helical implant 1 whereof thecoils have a flat ellipsoidal shape. As is understood, each coildefines, in the implantation tissue, a path going through points 25, 26separated from each other (cf. first angular position illustrated inbroken lines); when the implant 1 is rotated a quarter turn (cf. secondangular position shown in solid line), the two points 25, 26 are broughtcloser together, producing the contraction of the tissue located in thecentral perimeter of the implant.

FIGS. 19 to 22 illustrate an implant 1 having a cylindrical shape, i.e.having coils of a constant diameter, which is made of a shape memorymaterial. After placement of the implant 1 by screwing (cf. FIGS. 18 to20), a calorific contribution takes place, in particular through theimplementation of a difference in potential between the implant and thepatient's body. This calorific contribution produces, via shape memory,a reduction in the diameter of the coils of the implant 1, and thereforea contraction of the portion of the wall located in the perimeter of theimplant 1.

FIGS. 23 to 26 show another embodiment of the material for inserting theimplant 1, wherein the aforementioned hollow piercing needle 29 haslateral lumens 30 arranged through its wall, and wherein the wire 10 isequipped with deployable branches 10 a as described above. While thewire 10 is positioned in the needle 29 such that the branches 10 a areoutside the area of the lumens 30, the needle 29 is introduced throughthe annulus 103 and is positioned such that its lumens 30 are locatedbeyond the wall of the annulus 103 (cf. FIG. 23); the wire 10 is thenslid in the needle 29 to bring the branches 10 a across from the lumens30, which allow deployment of the branches 10 a (cf. FIG. 24), thenthese are brought into contact with the wall of the annulus 103 (cf.FIG. 25); for removal of the wire 10, this wire is slid in relation tothe needle 29 until it brings the branches 10 a into the portion of thisneedle located beyond the lumens 30 from the distal side, therebyachieving bending of the branches 10 a in the needle 29 and thusallowing removal thereof by sliding.

FIG. 27 shows that, according to one particular embodiment of theinvention, the proximal ends of two adjacent implants 1 can be connectedto wires 40 engaged in a catheter 41. These wires 40 are in a relativelystiff material able to be twisted, in particular in metal. Tensionexerted on the wires 40, then twisting of said wires, produces acontraction of the wall of the annulus 103 located between the implants1, in addition to the contraction produced by the implants 1 themselves,as shown by FIG. 28. Each wire 40 can in particular be connected to aloop formed by the proximal end of each implant 1, before insertion ofthe implant.

FIGS. 29 and 30 show the principle of a connection element 42 having acurved shape, able to connect three implants 1. This connection element42 can go from a first bend, which it has before implantation, to asmaller or rectilinear bend, which it has after implantation, so as toreduce the bend of the portion of the annulus 103 located between theimplants.

The connection element 42 can also go, via shape memory, from anelongated shape before implantation to a shortened shape afterimplantation, in order to produce a contraction of the annulus 103 dueto the three implants coming closer together. This connection element 42thus forms a stiffener.

FIGS. 31 and 32 show that an implant 1 can comprise a front coil 1 a oflarge diameter, and that the coils 1 a of several implants 1 can beinterconnected upon insertion of several consecutive implants,connecting these implants to each other.

As appears from the preceding, the invention provides an implant fortreating a heart valve, in particular a mitral valve of a heart, and amaterial for inserting this implant, which is completely satisfactoryand which makes it possible to perform either annuloplasties orstrengthening of valvular annuluses, under the best possible conditions.This implant and this material consequently have determining advantagesin relation to the existing techniques.

It goes without saying that the invention is not limited to theembodiment described above as an example, but that it extends to allembodiments covered by the appended claims.

1- Implant (1) for treating a heart valve, in particular a mitral valveof a heart, made up of a helically wound wire (2), characterized inthat: it has dimensions such that it can be screwed into the wall of theannulus (103) and/or into the cardiac wall (101) adjoining this annulus(103) so that a portion of said annulus (103) and/or of said wall (101)is located in the perimeter of the implant (1); and the implant (1)comprises at least one first coil able, upon screwing of the implant(1), to insert itself into said wall while having a first dimension andat least one second coil having a second dimension, or adopting thissecond dimension after implantation, said second dimension being smallerthan the first dimension such that the implant (1), once inserted,allows contraction of said wall portion located in the perimeter of thisimplant (1). 2- Implant (1) according to claim 1, characterized in thatsaid first coil(s) are located, in the direction of screwing of theimplant (1), in front of said second coil(s). 3- Implant (1) accordingto claim 1 or claim 2, characterized in that its coils have anon-circular shape, in particular oval or elliptical. 4- Implant (1)according to one of claims 1 to 3, characterized in that the wire (2)constituting the implant (1) is in a shape memory material, defining, ina first state, coils having said first dimension and, in a second state,coils having said second dimension. 5- Implant (1) according to one ofclaims 1 to 4, characterized in that the front end (5) of the wire (2)which constitutes it is pointed or sharp. 6- Implant (1) according toone of claims 1 to 5, characterized in that the wire which constitutesit has a same structure along its entire length. 7- Implant (1)according to one of claims 1 to 5, characterized in that the wireconstituting it comprises portions in a first material and portions in asecond material different from the first material. 8- Implant (1)according to one of claims 1 to 7, characterized in that the wire whichconstitutes it comprises portions having different structures, forexample solid, resistant portions and portions having a thinnercross-section able to break in case of exertion on the implant ofstresses directed radially outwardly. 9- Implant (1) according to one ofclaims 1 to 8, characterized in that it comprises radiopaque markersenabling its visualization through the body of the patient, inparticular markers making it possible to visualize the angularorientation of the implant when the latter comprises non-circular coils.10- Implant (1) according to one of claims 1 to 9, characterized in thatit comprises means ensuring its anchoring in the tissue with regard toscrewing or unscrewing. 11- Material including the implant according toone of claims 1 to 10, characterized in that it comprises means (40)making it possible to connect at least two adjacent implants (1)inserted in an annulus (103), so as to achieve a contraction of the wailof the annulus (103) located between the implants (1), in addition tothe contraction done by the implants (1) themselves. 12- Materialaccording to claim 11, characterized in that said means comprise wires(40) in a material able to be twisted, in particular in a metallicmaterial, connected to the proximal parts of the implants (1), thesewires (40) being engaged in a same catheter (41) then being twisted tobring the two implants (1) closer together. 13- Material including theimplant according to one of claims 1 to 10, characterized in that itcomprises curved connection means able to connect at least two implants,these connection means being able to go from a first bend, which theyhave before implantation, to a smaller or rectilinear bend, which theyhave after implantation. 14- Material including the implant according toone of claims 1 to 10, characterized in that it comprises connectionmeans able to connect at least two implants, these connection meansbeing able to go, via shape memory, from an elongated shape beforeimplantation to a shortened shape after implantation, in order toachieve a contraction of the valvular annulus due to the implants beingbrought closer together. 15- Material for inserting the implant (1)according to one of claims 1 to 10, or the material including thisimplant according to one of claims 11 to 14, characterized in that itincludes at least one catheter (11) able to deliver the implant (1),means (16) for moving the implant (1) longitudinally in relation to thiscatheter (11) and means (14, 15, 16) for driving the implant (1) inrotation along the axis of the implant (1). 16- Material according toclaim 15, characterized in that the longitudinal movement means comprisea push-rod (16) slidingly engaged in the catheter (11). 17- Materialaccording to claim 15 or claim 16, characterized in that the means fordriving in rotation comprise a wire (14) connected separably to the rearend of the implant (1). 18- Percutaneous intervention method forperforming the treatment of a heart valve, in particular to perform anannuloplasty, i.e. a reduction of a distension of the valvular annulus(103), or a strengthening of the annulus (103) of a normal valve;characterized in that it comprises steps consisting of: using theimplant (1) according to one of claims 1 to 10 and the materialaccording to one of claims 15 to 17; bringing the distal opening of thecatheter (11) comprised by the material across from the area designed toreceive the implant (1); moving the implant (1) forward in relation tothe catheter (11) while driving this implant (1) in rotation along itsaxis, in order to achieve screwing of the implant (1) into the annulus(103) of the valve to be treated and/or the cardiac wall adjoining thisannulus (103); if necessary, repeating the preceding steps so as toinsert as many implants (1) as necessary to perform the desiredannuloplasty and/or strengthening of the annulus (103). 19- Interventionmethod according to claim 18, characterized in that the step consistingof bringing the distal opening of the catheter (11) across from the areadesigned to receive the implant (1) is done by approaching the valvefrom one or the other of the sides of this valve, in particular,involving the treatment of a mitral valve, either using a ventricularapproach or an auricular approach.